You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

Abstract

Optoacoustic imaging is a rapidly developing area of biomedical imaging due its combination of rich optical
contrast and ultrasound depth penetration. Just like conventional pulse-echo ultrasound imaging, optoacoustic
tomography relies on the use of ultrasound detector arrays with a large number of elements. The precise
knowledge of the transducer’s sensitivity is crucial for the prediction of its performance for a given imaging
task. Sensitivity characteristics such as the central frequency and bandwidth are routinely characterized.
However, this characterization is typically performed solely under normal incidence since the measurement of
the angle and frequency depended sensitivity (directivity) is difficult and time consuming with existing
ultrasound characterization methods. We present a simple and fast characterization method for broadband
directivity measurements of the angular transducer sensitivity based on the optoacoustic effect. The method
utilizes a thin absorbing suture in order to generate omnidirectional and broadband optoacoustic signals,
which are calibrated using a needle hydrophone. We applied this method to characterize and compare the
directivity of a conventional piezoelectric (PZT) transducer to the directivity of a capacitive micromachined
ultrasonic (cMUT) transducer. Both technologies showed a similar broadband response at normal incidence
and the PZT transducer displayed a more than two times larger signal to noise ratio at normal incidence.
However, the cMUT transducer’s sensitivity was significantly less angle-depended and outperformed the
PZT’s sensitivity for angles larger than 20°.

Keywords/Phrases

Keywords

in

Remove

in

Remove

in

Remove

+ Add another field

Search In:

Proceedings

Volume

Journals +

Volume

Issue

Page

Advanced PhotonicsJournal of Applied Remote SensingJournal of Astronomical Telescopes Instruments and SystemsJournal of Biomedical OpticsJournal of Electronic ImagingJournal of Medical ImagingJournal of Micro/Nanolithography, MEMS, and MOEMSJournal of NanophotonicsJournal of Photonics for EnergyNeurophotonicsOptical EngineeringSPIE Reviews